I think you are way to caught up in the origination of the term.
The left uses phrases like Jim Crow, as a term to broadly brush anything they deem slightly racist, whether or not it has anything to do with Jim Crow laws or not.
This is the same thing. I had no idea what the orgination of the term “blood libel” was, until today, however, I think the term aptly applies to falsely accusing someone as having blood on their hands.
to=too